pneumographic

In the second set of experiments the reactor was directed simply to accompany the beating of a metronome by a light tapping with the forefinger on a rubber-surfaced tambour connected with a pneumographic registering pen, with which was aligned an electrical time-marker also actuated by the metronome.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889

The first of these consisted of a shallow Marey tambour, placed horizontally upon a table with its rubber film upwards, and connected by means of rubber-tubing with a pneumographic pen in contact with the revolving drum of a kymograph.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889

A Deprez electric marker, aligned with the pneumographic stylus, afforded a time record in quarter seconds.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889

The rate of revolution in the drum was so adjusted to the normal range of excursion in the pneumographic pen as to give sharp definition to every change of direction in the curve, which hence allowed of exact measurements of temporal and intensive phases in the successive rhythm groups.

Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Various 1889